Swaddling can cause hip troubles, doctors warn.

Swaddling a newborn has potential dangers, a new study has found.

One of the first things new parents do is wrap their babies up tightly and head home – but doctors are saying don’t do that. Well, don’t wrap them up so tightly.

A new study by The Medical Journal of Australia found a connection between swaddling and late diagnosis of developmental dysplasia of the hip (DDH).

The study found that about 44% of babies that were diagnosed with DDH after they were three-months-old needed surgery.  Whereas most cases that were picked up early could be treated without surgery.

Report author and paediatric orthopaedic surgeon Nicole Williams said: “There’s very good evidence that wrapping up babies with their legs tightly together is very bad for their hip development.”

“We’re worried that some babies are being swaddled as newborns and that’s predisposing them to developing hip troubles,” she said.

"In cultures where babies have been wrapped up with their legs together very tightly, there are very high rates of hip dysplasia.

"An example is Japan, where traditional swaddling with the legs out straight, meant they had very high rates of DDH  - 6% of babies".

In South Australia, where the study was conducted, the rates of DDH have increased more than threefold for babies over three months old.

Dr Williams says it coincided with "increased popularity of swaddling" and the "boom in the availability of swaddling cocoons -  many of which do not allow enough room for the baby hips to flex and abduct".

“Lots of babies are getting diagnosed after three months of age when it’s something that we were traditionally much better at picking up when they were newborn,” said Dr Williams.

So the study points to swaddling as a preventable cause of hip problems but the technique is not new.

"Swaddling is something that’s been around for a very long time and there’s even stories of Jesus being swaddled in a manger...It’s become popular again recently." she said.

The technique is a popular way to settle babies and is also thought to help them sleep on their backs.

However, doctors say the best position for baby hips to develop is when they are held "up and out". In medical terminology it's called "flexed and abducted" and is also known as the 'M' or 'frog-squat' position.

"In contrast, hip development can be affected if the baby legs are forced together out straight," said Dr Williams.

So should we stop swaddling our babies? Dr Williams isn't against swaddling entirely.

"I'm not anti-swaddling.  I just want to make sure people are doing it properly because they are trying to do the best thing for their bubs.

"We don’t want parents to be causing harm when they are trying to do the right thing."

Dr Williams says swaddling should be done in a way that allows "space for the hips to naturally flex and abduct" and cocoons should also have "ample space to allow the flexed, abducted position".

"It's not adequate to have stretchy material, there must be sufficient space," she said.

Dr Williams admits she used the technique with her daughter but urges caution.

"I wrapped up my little baby too, but I made sure her legs had lots and lots of space," she said.

The International Hip Dysplasia Institute has information on ways to safely swaddle your baby and carry your baby to promote healthy hip development.

Did you swaddle your baby?